October 20, 2005

Impotence drugs need stronger warning – group

by ssavage

By Susan Heavey

WASHINGTON (Reuters) - Drugs to treat erectile dysfunction
need stronger warnings on their packaging about the risk of
blindness, U.S. consumer group Public Citizen said on Thursday
in a petition filed with health regulators.

The U.S. Food and Drug Administration should "immediately
add a black box warning regarding the risks of drug-induced
blindness for the three phosphodiesterase 5 (PDE5) inhibitors
that are prescribed for the treatment of erectile dysfunction,"
Public Citizen's Health Research Group wrote.

Pfizer Inc.'s pulmonary hypertension drug Revatio, which
has the same active ingredient as its impotence drug Viagra,
should also carry a similar black box warning -- the strongest
warning the agency can require, the advocacy group said.

Earlier this year drugmakers agreed to put information on
their impotence drug labels about the possible vision loss,
called non-arteritic anterior ischemic optic neuropathy.

Viagra, Cialis, sold by Eli Lily & Co. and Icos Corp., and
Levitra, sold by GlaxoSmithKline, Bayer AG and Schering-Plough
Corp., now carry the new labels, which say the condition "has
been reported rarely."

Both the companies and the FDA have said the cause of the
blindness is not known.

But Public Citizen said 19 percent of all cases of the
vision disorder reported to the FDA since 1998 were among users
of Viagra.

"The fact that Viagra's large numbers of adverse reaction
reports occurred without any warnings to the medical profession
strongly suggests that Viagra is an important factor in causing
(ischemic optic neuropathy)," the petition said.

The current label warnings are inadequate, the group said.
"The wording is ambiguous and the location of this information
is buried," the petition said.

Public Citizen also called on the FDA to start a registry
of all patients who are diagnosed with the vision disorder. The
agency should also require manufacturers to send all U.S.
physicians a letter about the risk and call for pharmacists to
give FDA-approved leaflets with prescriptions.

FDA's handling of the blindness reports has been
questioned. In June, Senate Finance Committee Chairman Charles
Grassley, an Iowa Republican, requested internal FDA documents
and other information about why it took "so long" for the
agency to call for the label changes and notify the public.

Men most at risk for the vision loss are those older than
50 who have diabetes, heart disease, high blood pressure and
high cholesterol, among other ailments.